Tubular ice system for scale-up of progressive freeze-concentration

Technology for freeze concentration in the desalination industry

In conventional processes, such as evaporation, higher levels of concentration can be reached compared with freeze concentration or membrane techniques. However, the advantage of the freeze concentration technique is based on the quality of the product obtained due to the low temperatures used in the process, which makes it a very suitable technology for the processing of fruit juices. There are two basic methods for concentrating solutions by freezing: suspension and film freeze concentration. Suspension freeze concentration systems (FCS) already have operating equipment in the food industry, while film FCSs, also called layer crystallization, is still at an experimental stage. This review summarizes the most important studies relating to the suspension and film freeze concentration in fruit juices and sugar solutions, illustrating the different possibilities that freeze concentration has in the fruit juices industry; it also presents trends and suggests improvements for the future development of this technology. It is noted that most recent publications refer to the film FCS. The technology used to design, build and maintain layer crystallization equipment is simple and it can be available to any operator in the food industry, layer systems will be used in the future if their results can be improved in terms of ice purity and degree of fluid concentration.

Review. Freeze Concentration in the Fruit Juices Industry

Cryoconcentration is a natural phenomenon which occurs during the ice thawing. More concentrated phase is then separated from the initial solution. This phenomenon was exploited for scientific objectives and the results were impressive. The use of the cryoconcentration technology in the bio-food industry makes it possible to obtain products of high nutritive, biological and organoleptic value. The aim of this review was to trace a detailed synthesis of the basic principles of this concentration and extraction technique, to summarize in one document the potential and principal applications reported in the literature and to try to predict the future and the necessary conditions for the industrial success of this technology.

Cryoconcentration technology in the bio-food industry: Principles and applications

Application of progressive freeze-concentration for desalination

According to an extensive study conducted in the early nineties, the best method for treating hazardous caustic wastewater coming from an SMPO (styrene monomer/propylene oxide) production plant is the combination of freeze concentration followed by incineration of the concentrate. This work provides a thorough description of the principle of freeze concentration after the Niro freeze concentration process together with an example and an economical comparison with direct incineration.

Preconcentration of wastewater through the Niro freeze concentration process

The invention relates to an apparatus for the purification of a substance from a solution, a suspension or a mixture of liquids by crystallization, preferably in a continuous manner. The apparatus comprises a first crystallizer (1c) comprising an input (1) for receiving a liquid comprising the substance and an output (4) for discharging a slurry of liquid and crystals. The apparatus comprises also a first separator (1s) connected to the output 4 of the first crystallizer (1c) having a product output (2), and being with a residue output (5) connected to an input of a second crystallizer (2c), and a second separator (2s) being with an input connected to an output (6) of the second crystallizer (2c), a crystal output (7) of the second separator (2s) being connected to an input of the first crystallizer (1c).

Method and apparatus for recovering a pure substance from an impure solution by crystallization

The invention relates to a method for the purification or recovery of orthophosphoric acid rich streams by suspension-based melt crystallization. The orthophosphoric acid is crystallized as the hemi-hydrate form and subsequent separation of such crystals in a wash-column produce a high purity acid/water solution that has been depleted of most of the metals and impurities other than water, thereby separating an orthophosphoric acid rich feed liquor into an ultra-pure orthophosphoric acid hemi-hydrate and a mother liquor containing almost all impurities originally present in the feed. The orthophosphoric acid rich feed liquor typically contains no more than 15wt% water and 1wt% other impurities. Individual metal ion composition in the purified orthophosphoric acid product is in the range of 100 to1000 ppb (parts per billion = 1/1000 ppm) of each metal ion. The metal ion composition of the resulting purified product is thus typically below the detection limit of typical analysis equipment.

Purification of phosphoric acid rich streams

Abwasservorkonzentrierung nach dem Niro Freeze Concentration Process

The invention relates to a method for separating an isocyanate mixture which contains at least two isomers of the respective isocyanate and various additional impurities simultaneously into two product streams which are characterized by different ratios of the two main isomers and where none of two products have a purity of main isomers greater 99 wt.% by means of a suspension-based melt crystallization process combined with a subsequent separation of the crystals in a wash column.

Ray Sircy Ruemekorf

Papers

Preconcentration of wastewater through the Niro freeze concentration process

Method and apparatus for recovering a pure substance from an impure solution by crystallization

Purification of phosphoric acid rich streams

Abwasservorkonzentrierung nach dem Niro Freeze Concentration Process

Process for crystallizing and separating different diisocyanate isomers